Doing some thinking today and come to the conlusion that the most important part of Michael was timing.
Had the ridge been stronger it would have hit the Yucatan and probably dissipated or it would have maintained a more westward heading in the gulf and would have been sheared and weakened before landfall.
Had the trough been stronger, it would have been quickly pushed east over the FL peninsula or Cuba and then OTS or sheared into a mostly lopsided TS.
Or had the two not being placed perfectly to provide a massive southerly flow to create the massive deep moisture envelope that was in place and allowed dry air to take its toil.
Had the shear been stronger in the gulf it would have stayed weak or had the shear not existed it would have probably exploded before ERCs occured. That would have opened the door to dry air intrusion, and expanding storm size causing upwelling due to the low OHC over the gulf. Thus ending in the typical weakening to rapidly weakening gulf cane we all are used to.
Or the anomalous warm, untouched water in the gulf. Which a single strong cold front could have cooled.
Or the speed being faster and becoming Nate or the speed being slower thus making upwelling an issue.
Everything was in place perfectly to allow a hit on the northern Gulf and not just a hit but a hit from what could be upgraded to a Cat 5. From the speed to the eastward turn allowing the eyewall to close and the increased ventilation, along with perfect timing and very high cape. All had a part to allow it to absolutely thread the needle. There will be decades of intense study on this thing which is probably more anomalous than Sandy.